Home/ Questions/Q 1035427
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T14:32:26+00:00

I am trying to create a persisted computed column using CASE expression: ALTER TABLE

  • 0

I am trying to create a persisted computed column using CASE expression:

ALTER TABLE dbo.Calendar ADD PreviousDate AS 
case WHEN [Date]>'20100101' THEN  [Date]
    ELSE NULL
    END PERSISTED

MSDN clearly says that CASE is deterministic, here

However, I am getting an error:

Msg 4936, Level 16, State 1, Line 1
Computed column ‘PreviousDate’ in
table ‘Calendar’ cannot be persisted
because the column is
non-deterministic.

Of course, i can create a scalar UDF and explicitly declare it as deterministic, but is there a simpler way around this? I am already in the middle of getting the latest service pack. Thanks.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    You need to CONVERT ‘20100101’ with a style.

    Source or target type is datetime or
    smalldatetime, the other source or
    target type is a character string, and
    a nondeterministic style is specified.

    So, try this:

    ...WHEN [Date] > CONVERT(datetime, '20100101', 112)....

    Date parsing from string can be unreliable as I’ve answered before (mostly in comments)

    Edit:

    I wouldn’t say it’s a bug, but SQL Server asking for 100% clarification. yyyymmdd is not ISO and SQL Server parsing yyyy-mm-dd is unreliable (see my answer link)

    • 0